[Dave2024]

Hi, can someone identify some things about this spindle motor and possible point me in the direction of finding one that I can replace it with? Im looking for both a motor and a drive mostly interested in either an AC servo or a BLDC servo something that can be powered on 120v-220v..

Theres a few other questions: Is this motor a Nema frame type of motor? Is it like a NEMA-42 or a NEMA-52 or how can I tell?

All I know is the shaft size is 14mm and 40mm long
The bolt pattern is 70mm X 70mm

Can someone show me options for a motor with these same dimensions that is a servo type motor and can do 3000–5000RMP? Thanks


I did manage to find a motor that looked about the same but it had no information on it and is possibly wont have the correct torque and rpm

[peteeng]

Hi Dave - A clear photo of the name plate would help. Peter

[joeavaerage]

Hi,
firstly the NEMA42 or NEMA52 is easy. The number refers the the size of the servo across the flats. Thus a Nema42 is 4.2 x 25.4=106.7mm across the flats while a NEMA52 is 130mm across the flats.

NEMA is a US designation while many of the devices you'll be looking at will be Chinese made simply because they are so much cheaper, and by-in-large the Chinese is all metric....and so you'll not find NEMA42 size.

I use and recommend Delta servos, a Taiwanese brand made in China. They are good quality, support, documentation and most importantly free set-up and tuning software at fair prices.

There are cheaper Chinese brands and they all seem to work OK but the support is questionable, the documentation poor or worse and often NO set-up and tuning software. If you've never had a servo before
don't go there. Sure it'll be cheap, but you'll want to throw it in the junk pile before you get it to go.

I use 750W Delta B2 series servos on my machine. The are 100mm across the flats. You might say they are the 'metric equivalent' of a NEMA34 (actually NEMA 34 is 86mm across the flats).

They are 2.4Nm S1 rated, 7.1Nm overload, 3000rpm rated and 5000rpm max. I pay $438USD plus shipping for them, and I've bought 7 in the last three years.

https://www.fasttobuy.com/flange-80m...er_p28084.html

This one, from the same company is 2kW S1 rated or 6.4Nm, 19.1Nm overload at 3000 rpm but with a max speed of 5000rpm. The kit (servo drive and cables ) is $895USD plus shipping and would make a kick-arse spindle motor.

https://www.fasttobuy.com/delta-2kw-...nc_p33936.html

Craig

[Dave2024]

Hi thanks for checking this post out but heres a photo of the plate. I couldent figure out how to edit a post here on CNCZone to add more pictures. Anyhow thanks. This has been the biggest headache trying to find find motors like this they all are missing information.

https://flic.kr/ps/44oSBs

[joeavaerage]

Hi,
your 70mm x 70mm bolt pattern corresponds to a pitch circle of 98.995mm which is near-as-dammit the pitch circle of a NEMA34 servo.

Thus if you need to match the bolt holes exactly then you need a genuine NEMA34 servo. Delta do at least one model of 86mm, but you might be better off looking at DMM. A Canadian brand made
in China, good quality and support at fair prices. They compete with Delta with regards performance and cost. Being Canadian they have more NEMA34/86mm models as they sell into the US and the Yanks
love their NEMA s****t.

https://www.dmm-tech.com/ac_servomotor_main_a1.html

[Dave2024]

Hi,
firstly the NEMA42 or NEMA52 is easy. The number refers the the size of the servo across the flats. Thus a Nema42 is 4.2 x 25.4=106.7mm across the flats while a NEMA52 is 130mm across the flats.

NEMA is a US designation while many of the devices you'll be looking at will be Chinese made simply because they are so much cheaper, and by-in-large the Chinese is all metric....and so you'll not find NEMA42 size.

I use and recommend Delta servos, a Taiwanese brand made in China. They are good quality, support, documentation and most importantly free set-up and tuning software at fair prices.

There are cheaper Chinese brands and they all seem to work OK but the support is questionable, the documentation poor or worse and often NO set-up and tuning software. If you've never had a servo before
don't go there. Sure it'll be cheap, but you'll want to throw it in the junk pile before you get it to go.

I use 750W Delta B2 series servos on my machine. The are 100mm across the flats. You might say they are the 'metric equivalent' of a NEMA38 (actually NEMA 38 is 96mm across the flats).

They are 2.4Nm S1 rated, 7.1Nm overload, 3000rpm rated and 5000rpm max. I pay $438USD plus shipping for them, and I've bought 7 in the last three years.

https://www.fasttobuy.com/flange-80m...er_p28084.html

This one, from the same company is 2kW S1 rated or 6.4Nm, 19.1Nm overload at 3000 rpm but with a max speed of 5000rpm. The kit (servo drive and cables ) is $895USD plus shipping and would make a kick-arse spindle motor.

https://www.fasttobuy.com/delta-2kw-...nc_p33936.html

Craig

Ok so I should be looking for the flange size then? The 70mm flange is the one that fits my current mill head then I just have to be sure its rated to 3k-5k rpm and I should be ok rite? There's no difference between a carnage motor and a spindle? They can be used interchangeable except the spindle needs more torque or at least higher rpm? That and the shaft needs to be 14mm in my situation with a key

[joeavaerage]

Hi,
You need a 750W 86N DHT and match that with a DYN4 drive....don't go cheap and get a DYN2....you'll miss out at the top end.

Craig

[joeavaerage]

Hi,

The 70mm flange is the one that fits my current mill head

You posted a 70mm x 70mm bolt hole spacing, and here you are saying a 70mm flange. Which is it???

Craig

[joeavaerage]

Hi,
a servo can be used as a spindle motor.

Most servos, for example my 750W Deltas have a rated speed and a max speed. The rated speed is 3000rpm. So it can develop its rated torque, 2.4Nm at 3000rpm. But it has a max speed of 5000rpm
but at somewhat reduced torque. 2.4 x 3000/5000= 1.44Nm.

This is called 'Field Weakening' and is a very interesting property of Field Oriented Control motors like servos. It adds flexibilty that regular brushed DC servos just cannot match.

Typically a servo that uses this feature make only modest use of it, for example my servos are 3000 rated and 5000 max. You could make it more dramatic but servos tend not to do so.
There are BLDC motors that do exploit field weakening to a much greater extent and find use as spindle motors.

For example a 3kW spindle motor that is rated at 2000rpm or 14.3Nm but has a max speed of 8000rpm albeit with only 3.6Nm at 8000rpm....still very versatile.

There are many dozens on Aliexpress, but I don't think you'll find any as small as NEMA34.

Craig

[Dave2024]

Hi,


You posted a 70mm x 70mm bolt hole spacing, and here you are saying a 70mm flange. Which is it???

Craig

Bolt lol sorry

[joeavaerage]

Hi,
the DMM one I listed will do 3000rated and 5000rpm max, is a MEMA34 frame, whats no to like about it?

Craig

[Dave2024]

Hi,
a servo can be used as a spindle motor.

Most servos, for example my 750W Deltas have a rated speed and a max speed. The rated speed is 3000rpm. So it can develop its rated torque, 2.4Nm at 3000rpm. But it has a max speed of 5000rpm
but at somewhat reduced torque. 2.4 x 3000/5000= 1.44Nm.

This is called 'Field Weakening' and is a very interesting property of Field Oriented Control motors like servos. It adds flexibilty that regular brushed DC servos just cannot match.

Typically a servo that uses this feature make only modest use of it, for example my servos are 3000 rated and 5000 max. You could make it more dramatic but servos tend not to do so.
There are BLDC motors that do exploit field weakening to a much greater extent and find use as spindle motors.

For example a 3kW spindle motor that is rated at 2000rpm or 14.3Nm but has a max speed of 8000rpm albeit with only 3.6Nm at 8000rpm....still very versatile.

There are many dozens on Aliexpress, but I don't think you'll find any as small as NEMA34.

Craig

Ok yea im hoping to replace this motor and the drive. Its a 300v BLDC hall controlled motor. Thats all I know about it. My plan is to find one that's got a built in encoder or can have an encoder added to it but this is my first time ever having to mess with replacing a spindle motor of this type and there's like no youtube videos or anything you can find through a google search or anything. I do appreciate your helping me out with this though. Im going to start researching the Delta motors and drives and see if there's any that have the 70mm bolt patterns and at least can do 5k rpm

[Dave2024]

Hi,
the DMM one I listed will do 3000rated and 5000rpm max, is a MEMA34 frame, whats no to like about it?

Craig

Lol sorry I'm just getting started. Trust me I'm going to be thoroughly researching everything about the two recommendations you gave me. I'm just slow is all. I will defiantly have a look at that DMM NEMA34 here in a few just haven't gotten half way through the Delta yet. I might have to take a break but awesome thanks

[joeavaerage]

Hi,
an AC servo is probably the most expensive option, but in my opinion still the best. Servos are very power-dense, probably the most power dense technology out there. Additionally with field weakening
they have a greater rpm range than would otherwise be possible. They are of course position capable which many spindle motors are not which is a handy feature if you want to try your hand at rigid tapping
or an indexed ATC. The three to fourfold overload a capacity of a servo would tend to make you think its much more powerful than the nameplate would suggest. The probability of a good to excellent result is high
with a servo, which is not to say that there are not other solutions, but rather the probability of a good result with those other solutions is not as good.

Quite some years ago I made a servo driven spindle. I wanted something with much lower rpm (than my regular 800W 24000rpm asynchronous spindle). I used a second hand Allen Bradley 1.8kW AC servo,
6.1Nm S1 rated, 18Nm overload, 3500rpm rated but with no field weakening, ie 3500rpm is its rated and max speed. I use for steel and stainless. Takes a few minutes to swap out. Does not get a huge amount of use,
probably ten hours a month or so. It is 98mm across the flats, so does not really fit any of the NEMA designations. I can tell you that while its supposedly 2.6hp you'd swear it were more....it really rocks along!!!

Craig

[Dave2024]

Hi,
an AC servo is probably the most expensive option, but in my opinion still the best. Servos are very power-dense, probably the most power dense technology out there. Additionally with field weakening
they have a greater rpm range than would otherwise be possible. They are of course position capable which many spindle motors are not which is a handy feature if you want to try your hand at rigid tapping
or an indexed ATC. The three to fourfold overload a capacity of a servo would tend to make you think its much more powerful than the nameplate would suggest. The probability of a good to excellent result is high
with a servo, which is not to say that there are not other solutions, but rather the probability of a good result with those other solutions is not as good.

Quite some years ago I made a servo driven spindle. I wanted something with much lower rpm (than my regular 800W 24000rpm asynchronous spindle). I used a second hand Allen Bradley 1.8kW AC servo,
6.1Nm S1 rated, 18Nm overload, 3500rpm rated but with no field weakening, ie 3500rpm is its rated and max speed. I use for steel and stainless. Takes a few minutes to swap out. Does not get a huge amount of use,
probably ten hours a month or so. It is 98mm across the flats, so does not really fit any of the NEMA designations. I can tell you that while its supposedly 2.6hp you'd swear it were more....it really rocks along!!!

Craig

Wow that's a nice spindle motor! So where dose anyone acquire a spindle motor of such quality? I will slave my ass off for one of those just why isn't there any so easily available? With the Allen Bradley driver what model is that? I've bean reading the manual for them like the bible lately and still in hell over something so simple that I'm about to give up on. It really pisses me of that trying to upgrade a spindle motor requires contacting the CIA or some **** these days? Lol

[joeavaerage]

Hi,
I was quite lucky. I bought off the New Zealand local auction site TradeMe. New Zealand is a small market and so when unusual items come up you can often get a bargain
I paid $700NZD ($420USD) for the servo and matching Ultra 3000 20A drive. The cables I had to buy/make. I was able to identify the encoder plug and made the encoder cable for the price
of the plugs and cable, about $100NZD. The main cable however I could not buy the specialist plug but was able to buy a complete new old stock Allen Bradley cable for $150USD.
I also ended up buying the setup software, it is mandatory for Allen Bradely drives, you cannot program them manually. The software cost $200NZD direct from Rockwell.

All up I paid $1450NZD ($870USD) for a 1.8kW servo. I thought I did OK, not cheap or free, but not too bad either.....until the end of last year. When it was not in use I used to have it lying in the bottom
of my mill enclosure. It was not as well sealed as I thought and coolant got in and buggered up the optical encoder. Very, VERY, VERY annoyed with myself!!! Eventually I found another identical servo
in the US for $170USD...but it was rough. Looked like it had done a million miles already! I took a chance, the vendor reckoned it was still working, and so it proved to be. Shipping to New Zealand is not cheap, ever.
So what with shipping, local tax and currency conversion it cost me $635NZD. Needless to say I don't allow coolant to get at this one.

It was touch and go whether I repaired what I had or bought a new 2kW Delta servo kit. Ultimately it was cheaper to repair what I had, but there is a risk, and it worked out in my favor this time.

I am risk averse. The more money I pay the surer I need to be that whatever it is will be good. Something cheap I might chance it.....but expensive items NO BLOODY WAY! The new 2kW Delta was a little over double the price of the
second hand Allen Bradley. That I had forced this decision on myself by virtue of not being adequately careful with what I already had is very galling.

Craig

[Dave2024]

Hi,
I was quite lucky. I bought off the New Zealand local auction site TradeMe. New Zealand is a small market and so when unusual items come up you can often get a bargain
I paid $700NZD ($420USD) for the servo and matching Ultra 3000 20A drive. The cables I had to buy/make. I was able to identify the encoder plug and made the encoder cable for the price
of the plugs and cable, about $100NZD. The main cable however I could not buy the specialist plug but was able to buy a complete new old stock Allen Bradley cable for $150USD.
I also ended up buying the setup software, it is mandatory for Allen Bradely drives, you cannot program them manually. The software cost $200NZD direct from Rockwell.

All up I paid $1450NZD ($870USD) for a 1.8kW servo. I thought I did OK, not cheap or free, but not too bad either.....until the end of last year. When it was not in use I used to have it lying in the bottom
of my mill enclosure. It was not as well sealed as I thought and coolant got in and buggered up the optical encoder. Very, VERY, VERY annoyed with myself!!! Eventually I found another identical servo
in the US for $170USD...but it was rough. Looked like it had done a million miles already! I took a chance, the vendor reckoned it was still working, and so it proved to be. Shipping to New Zealand is not cheap, ever.
So what with shipping, local tax and currency conversion it cost me $635NZD. Needless to say I don't allow coolant to get at this one.

It was touch and go whether I repaired what I had or bought a new 2kW Delta servo kit. Ultimately it was cheaper to repair what I had, but there is a risk, and it worked out in my favor this time.

I am risk averse. The more money I pay the surer I need to be that whatever it is will be good. Something cheap I might chance it.....but expensive items NO BLOODY WAY! The new 2kW Delta was a little over double the price of the
second hand Allen Bradley. That I had forced this decision on myself by virtue of not being adequately careful with what I already had is very galling.

Craig

Your in New Zealand, that's awesome! I'm a long ways away from there lol. Its cool that your helping me out with this and also thanks. So you think I should try and find one of the Allen Bradley drives? It sounds like there pretty good if you can find one in good condition still used for cheap. I often wonder what kind of machines the used ones come out of and what they are being replaced with. There probably replaced some dialed DMM setup bran new and fresh. For me though I don't have the skills to just go blow $4800NZD on some new equipment but if I could I would because I really enjoy this hobby and is were the extra flow would go after work, well besides beer stripers and the casino... Lol JK about the casino and all that, but I would like to get a nice setup like you have with the Allan Bradley and encoders and all that. I'm going to look and see if I can find one! Thanks!

[joeavaerage]

Hi,

So you think I should try and find one of the Allen Bradley drives?

No, I don't think so. Its not that they are not good, they are, very good in fact. The problem is that they are just becoming hard to find. My servo is from 2005. Allen Bradley is good, and compares with Yaskawa, Siemens and Fanuc,
all very good but hugely expensive. Its not impossible that you stumble onto a bargain, but just not that likely.

The reason servos come onto the second hand market is because the drive blows up and its cheaper to buy a new and matching servo and drive kit than it is to replace what may now be a marginally obsolete drive.
Remember I paid nearly as much for the cables and software than I paid for the servo and drive. If you do try second hand make sure you can find the drive, cables and software....or your cheap servo starts to look like
an orphan.

Delta and DMM are two good quality brands, I'm not suggesting they are as good as Yaskawa, but they compare favourably at a fraction of the price.

The same company I buy Delta servos from sell their own brand called ToAuto. I have no reason to believe they will not work as advertised and I have faith in the company. To date I've always paid a little extra to get Delta.
Why would I pay $300USD for a ToAuto servo kit with the question marks it brings when I can have a Delta servo kit of the same size for $438USD?. None-the-less this is a ToAuto servo kit. Note it is an 86mm frame, ie
would bolt into your machine, excepting that the shaft is 16mm not 14mm....for $292USD. I see its rated to only 2000rpm....and no mention if it can go faster, ie field weakening.

https://www.fasttobuy.com/nema-34-el...ng_p35887.html

I have set-up and tuned quite a few servos now from different manufacturers, mostly with the advantage of set up and tuning software. All AC servos tend to be very similar to each other. If a manufacturer adds a feature you
can be bound that they will all do so. I have little doubt therefore that I could set up a ToAuto servo, especially as it is only for a spindle, but to date I've stuck with Delta....that's just me.

Buying second hand and mixing and matching servos, drives and cables is a good way to waste time and money. You really need to be confident that you can get a result....otherwise don't bother.
I think even cheap Chinese servo kits would be less risky than mixing and matching.

This is what I would recommend. Its a Delta B2, 750W. Note it is 80mm frame (not your NEMA34 or 86mm frame) so you would have to re-drill the holes or make an adapter plate and it has a 19mm shaft.
Its rated at 3000rpm, but will go up to 5000rpm for $438USD. I've had mine up to 5000rpm....they sing!

https://www.fasttobuy.com/flange-80m...er_p28084.html

Craig

[joeavaerage]

Hi,
this is the sort of thing that is still available:

https://www.ebay.com/itm/11616324733...Bk9SR-bZrfX2Yw

Its 2kW and rather bigger than your 86mm frame, in fact this is a 100mm frame, same as my 1.8kW unit. To match this you really want a 30A drive, but a 20A would be OK.

This is a 20A:

https://www.ebay.com/itm/32565263220...Bk9SR8a3zvX2Yw

While this is a 30A:

https://www.ebay.com/itm/36484599917...Bk9SR9Tc2vX2Yw

So just the servo and the drive are over $800USD and you have still yet to get cables and software. A 2kW Allen Bradley would make a nice spindle motor to be sure, but for the same money I could buy a brand new 2kW
Delta servo, complete with cables etc. I think I'd rather have a new Delta rather than a second hand Allen Bradley.....my choice of course.

Craig

[joeavaerage]

Hi,
I saw this, its 2kW S1 rated, 4.75Nm rated and has cables for $149. It has a 100mm frame so is bigger and considerably more powerful than what you have....but see the price...$149USD.
You'd want a 20A of 30A drive, but the price is coming down to the point 'you might just risk it'.

Craig

https://www.ebay.com/itm/27638522596...Bk9SR9q53vf2Yw